Wall corner construction



May 5, 1970 J. ALL'EAUME I 3,510,273

WALL comma coNsTRucTIon 5 Sheets-Sheet 1 I Filed Jan. 3, 1966 JEAN ALLEAUME May 5, 1970 J. ALLEAUME WALL CORNER CONSTRUCTION 5 Sheets-Sheet 2 Filed Jan. 5. 1966 J. ALLEAUME WALL CORNER CONSTRUCTION May 5, 1970 5 Sheets-Sheet 3 Filed Jan. 5, 1966 J. ALLEAUME WALL CORNER CONSTRUCTION May 5, 19 70 5 Sheets-Sheet 4 Filed Jan. 3, 1966 e 5 Y W W T a i -m m 5m, m 4 a J y 5, 1970 v J. ALLEAUME 3,510,278

WALL CORNER CONSTRUCTION Filed Jan. 3, 1966 5 Sheets-Sheet 5 United States Patent Office 3,510,278 Patented May 5, 1970 3,510,278 WALL CORNER CONSTRUCTION Jean Alleaume, Saint-Cloud, France, assignor to Technigaz, Paris, France, a corporation of France Filed Jan. 3, 1966, Ser. No. 518,111

Claims priority, application France, Jan. 5, 1965, 918, Patent 1,459,749 Int. 'Cl. B22f 5/00 US. Cl. 29-183 Claims ABSTRACT OF THE DISCLOSURE A flexible sheet having two or three series of parallel corrugations, said series being orientated in uniformly distributed angular directions whereby the zones of intersection contain one corrugation of each series, each such zone of intersection of n corrugations having the shape of a 2n-pointed star-shaped pyramid projecting from the same side of the sheet as the corrugations, such that the pyramid crests and troughs regularly alternate with one another, whereas said crests or troughs lie together with respective crests of the n corrugations at the zone of intersection in a plane normal to the initial sheet surface.

The present invetnion has essentially for its objects a device constituting a flexible wall element and its various applications, notably in the construction of fluid-tight enclosures such as tanks, cisterns, reservoirs, vats or like vessels, intended for example but not exclusively for the transport and/or storage or cryogenic preservation of strongly cooled fluids, more particularly liquefied gases at very low temperatures and at a pressure approximating the surrounding atmospheric pressure.

Such a device is designed for example with a view to constitute the internal envelope or primary barrier (with a relatively thin and flexible wall) of a so-called built-in tank bearing against a resistant surrounding supporting structure. These tanks may also be used'at high temperatures and pressures in safety enclosures of nuclear installations, or in the construction of nuclear reactor casings. According to the prior known state of the art, the wall element comprises a plurality of rectilinear identical corrugations of substantially dihedral isohedral configuration, which project unilaterally and intersect one another, these corrugations being preferably disposed at spaced intervals according to a regular pattern wherein the waves form therebetween equal separate substantially flat areas disposed substantially symmetrically in relation to the central intersection axes extending at right angles to the initial plane of the wall element. Still according to the aforesaid prior art, the Wall element comprises two orthogonal series of parallel corrugations all projecting on the same face with respect to the initial plane of the wall element, the folding angles being determined in such a manner that no material projects from the face opposite to said initial plane in case of variation in the height or altitude of the waves of the two wave systems of said orthogonal pattern, for example as a consequence of heat distortion. In this known wall element the common intersection solid of each pair of intersecting waves is a projecting polyhedral angle having an octahedral star-like regular pyramidal surface with the end points of the star arms of the base polygon lying substantially in the initial plane of the wall element, notably in the folding configuration with zero wave opening angle.

The object of the present invention is to generalize the known vfolding principle set forth hereinabove while preserving the advantageous feature of permitting likewise the absorption of the heat contraction and expansion in all directions. The wall element according to this invention s charatcerized in that it comprises at least two or more intersecting groups of substantially parallel corrugations wherein the waves are uniformly distributed about each common center of intersection and the convergent successive edges, even in number, of the alternatively projecting and concave dihedrons of each aforesaid pyramidal angle, lie respectively in the successive planes of symmetry of the intersection configuration which pass through the aforesaid normal central axis. Thus, the principle of intersecting groups of parallel corrugations is also applied to an arbitrary number, possibly more than two, of corrugation groups, the intersection angels being in this case also arbitrary and depending essentially on the number of intersecting groups of parallel corrugations. In each group of parallel corrugations, the relative spacing of the crests of two successive parallel waves is greater than the width measured at the base of each wave, in order to constitute substantially plane polygonal areas in the form of rectangular or square quadrilaterals in the case of two groups of corrugations and of triangles in the case of a greater number of corrugation groups.

Other features and advantages of the present invention will appear more clearly as the following description proceeds with reference to the accompanying drawings illustrating diagramatically by way of example various forms of embodiment of the invention. In the drawings:

FIG. 1 is a perspective view showing one element or portion of a wall or plate according to one form of embodiment of the invention, and comprising three intersecting groups of parallel corrugations, wherein each solid dodecahedral star-like angle of intersection penetrates into the convergent waves respectively with its projecting arms or edges;

FIG. '2 is a perspective view showing a second form of embodiment of the invention, comprising two orthogonally intersecting groups of parallel corrugations, wherein each solid star-like octahedral solid angle of intersection has its projecting arms or edges disposed respectively between the convergent waves penetrating with their convex dihedrons into said solid angle;

FIG. 3 illustrates a modified form of embodiment of the construction shown in FIG. 2, which comprises three groups of parallel corrugations intersecting each other at 60; and

FIGS. 4, 5 and 6 are fragmentary perspective views of a zone of intersection of the constructions shown on FIGS. 1, 2 and 3, respectively.

The form of embodiment illustrated in FIG. 1 constitutes a generalization of the folding or pleating system described and illustrated in the aforesaid prior state of the art. The metal plate element 1 comprises three groups of parallel, substantially dihedral corrugations designated respectively by reference numerals 2a, 2b and 20, which project on the same face of the initial sheet-metal plane and constitute on this surface a Wave pattern bounding between the adjacent waves substantially plane triangular areas or zones 3. Since this pattern of rectilinear waves is regular or, in other words, the relative angular spacing of the convergent rectilinear waves at each intersection such as 4 is uniform or equal about the intersection point, the directions of any pair of adjacent waves form an angle of 60 with each other. As a rule, if the wave pattern consists of n groups of corrugations, the value of the plane angle formed between any pair of successive or adjacent waves at each intersection is n.

The solid common to each intersection 4 consists of a pyramidal or polyhedral angle having a vertex 0 and a polygonal base 5 consisting of a regular, concave or star-like polygon. In the present instance this polygon is dodecagonal so that the aforesaid pyramidal angle is a dodecahedral angle. As a rule, in the case of n groups of corrugations, the base polygon of the aforesaid pyramidal angle will have 4 n sides and the pyramidal angle will have 4 it faces.

The convergent edges such as OA, OB, etc. of the projecting or convex dihedrons of each pyramidal angle lie in the longitudinal planes of symmetry of waves 2 which are respectively coincident with their crest edges 6, these planes being substantially perpendicular to the initial plane of the metal plate or sheet 1. The configuration of the penetration of the projecting or convex dihedrons of the pyramidal angle 4 into each wave 2 consists of a concave tetrahedral angle of which two adjacent faces 7 and 8 constitute the faces of said projecting or convex dihedron, and the other two triangular faces 9 and 10 pertain to the said wave 2 and form a concave dihedron of which the edge MA connects the adjacent end of crest 6 of said wave to the crest or edge OA of said pyramidal angle. The two faces 9 and 10 merge into the side faces of the wave 2 concerned, respectively through a convex folding to form a projecting dihedral angle (having a crest MN or MN) leading to the vertex of the intersection angle formed by edges 11a and 11b of the concave folds at the base of the two adjacent waves 2a and 2b.

The convergent edges such as ON, ON, etc., of the concave dihedrons of pyramidal angle 4 lie in the normal bisector planes of each pair of successive intersecting Waves or, in other words, in the bisector planes of the angles such as 76 formed by the intersection of the base edges such as 11a and 11b of said waves. These edges ON, ON etc., lead respectively to the points of intersection of the pairs of adjacent concave folding edges, such as 11a, 11b, at the base of the successive Waves.

It is a simple matter to prove that if it is desired that points such as A, B, etc., forming the vertices or peaks of the star constituting the base polygon 5, especially in the folding configuration having a zero wave opening angle, lie substantially in the initial plane 15 of sheet 1,

the value of the flat angle, such as M bk, of the lateral face terminating each wave at the intersection, must be substantially 15. It is also easily proved that, as a rule, in the case of a number n of corrugation groups, the value of this flat angle is 180/ 4n.

For symmetry reasons, any displacement of material, which is due to a heat distortion in the direction of a wave is attended by an equal displacement in the other wave directions and this property is also found in the other two forms of embodiment described hereinafter.

FIG. 4 shows a fragmentary perspective view at a larger scale of one zone of intersection of corrugations of the structure illustrated in FIG. 1.

FIGS. 2 and 3 illustrate exemplary forms of embodiments of the present invention wherein the projecting dihedrons of each pyramidal intersection angle do not penetrate into the convergent waves adjacent to said pyramidal angle but lie in the respective angles of intersection of said waves.

FIG. 2 illustrates this typical case comprising two orthogonally intersecting groups of parallel corrugations 12a and 12b forming at each intersection an octahedral pyramidal solid angle 13 having a vertex and a base consisting of a skew polygon forming in plane development a regular four-armed star having vertices or points A, B, C, D. These vertices or points of the arms of star 13 lie respectively at the points of intersection of the pairs of adjacent concave folding edges such as 14a, 14b at the base of the successive convergent waves, the vertices such as N N N N of the concave angles of this star lying respectively on the crest edges such as 15 of said waves. Thus, the convergent waves penetrate respectively into the concave dihedrons of the pyramidal angle 13. In this specific form of embodiment, with two orthogonally secant groups of parallel waves or corrugations, the wave pattern or system determines on the initial plane of the sheet metal a checked pattern consisting of rectangular flat areas.

FIG. 5 shows an enlarged fragmentary perspective view of one zone of intersection of corrugations of the construction illustrated in FIG. 2.

FIG. 3 illustrates a modified form of embodiment of the same arrangement wherein more than two intersecting groups of parallel corrugations are provided. In this example, three such groups are actually provided. FIG. 6 shows at a larger scale a fragmentary perspective view of one zone of intersection of corrugations belonging to the construction illustrated in FIG. 3.

This example compares with the structure shown in FIG. 1 since the relative angular spacing of the corrugations or waves about each common center of intersection is also As in FIG. 1, the fiat zones or areas left in the sheet metal by the wave pattern formed in the initial sheet have a triangular configuration. As already explained hereinabove, the number of groups of corrugations or pleats is definitely immaterial and may also be selected among relatively high figures. if desired.

It will be noted that in the forms of embodiment similar to those of FIG. '1 or resulting from modifications thereof, for example by altering the number of intersecting groups of parallel corrugations, the base polygon of each solid pyramidal angle of intersection is substantially fiat and advantageously located in the initial plane of the sheet, whereas in the forms of embodiment similar or related to those illustrated in FIGS. 2 and 3, the base polygon bounding each solid pyramidal intersection angle is a skew star-like regular polygon, since the arms of the star constituted by this solid pyramidal angle respectively overlap the convergent waves leading to said intersection; in other words, the portions of projecting dihedrons which constitute respectively the arms of said star, are positioned respectively in the angles of intersection of the convergent waves, whereby the edges of the portions of said concave dihedrons of said solid pyramidal angle, which lie between the arms of said star, lie respectively in the planes perpendicular to the initial plane of the sheet, which contain the crest edges of the convergent waves leading to said intersection.

In the examples illustrated in the figures, each solid pyramidal angle has a pointed vertex, as shown, but it is clear that truncated solid pyramidal angles, that is, angles having the shape of a truncated pyramid formed at the top with a small polygonal base either substantially flat or more or less concave or convex, may also be used. On the other hand, it is also obvious that in actual manufacturing practice the edges are not exactly dihedral sharp edges consisting of a single straight line, but rounded fillets or joining surfaces.

The corrugations are shown in the drawings as having a substantially dihedral configuration. Of course, it would not constitute a departure from the present invention to provide substantially prismatic or polyhedral corrugations, for example three-faced corrugations (i.e., two lateral faces and a top face), thus altering correspondingly the configuration of each solid pyramidal intersection angle and forming therein additional edges of dihedrons, so-as to obtain therein the shape of a truncated prism or pyramid.

Of course, the present invention should not be construed as being limited by the various forms of embodiment shown, described or suggested herein, since many modifications may be brought thereto without departing from the scope of the invention as set forth in the appended claims.

What I claim is:

1. A flexible sheet-like plate element at least one portion of which is formed with three sets of substantially parallel transversely equally spaced, identical, symmetrical, integral corrugations shaped as salient dihedrons of substantially uniform cross-section, entirely projecting all with their raised convex crest portions from a same side of said plate element without any projection of material from the opposite side thereof, the corrugations of each set intersecting those of the other sets at common zones of intersection containing each one corrugation of each set, the directions of said sets intersecting each other at equal angles of 60, so that said corrugations are uniformly distributed in a network of regular pattern consisting of adjacently juxtaposed equilateral triangles defining substantially smooth, uncorrugated, equilateral, triangular, separate areas located in the initial sheet surface, each zone of intersection together with its associated corrugations being substantially symmetrical about a central axis normal to the initial sheet surface, each zone of intersection comprising a regular pyramid having its vertex on said central axis and protruding from the same side of said plate element as said corrugations, said pyramid having twelve triangular faces meeting along the edge lines of and forming regularly alternating salient and reentrant, successively adjacent, dihedral angles defining corresponding ridges and troughs around the sloping sides of the pyramid and arranged opposite by pairs, said ridges lying together with corresponding corrugation crests in the longitudinal planes of symmetry of the corrugations respectively whereas said troughs are located in the bisecting planes, respectively, of the angles of intersection between successive corrugations, the pyramid base being a regular six-pointed star-shaped, twelve-sided polygon, each re-entrant angle of which has its apex located at the meeting point of the two adjacent concave fold lines lying in the initial sheet surface at the base of two successive converging corrugations, whereas each star limb extends endwise into between both side faces of a corrugation with the corresponding star point lying below the crest of said corrugation and being connected with said crest by a sloping edge line of a concave fold formed in said crest, said sloping edge line making an obtuse angle with the adjacent ridge of said pyramid and said plate element having a wholly geometrically developable surface throughout with merely folded features made in one piece with said plate element.

2. A plate element according to claim 1, wherein the crest of each corrugation terminates at each zone of intersection by dividing into two convex fold lines falling downwards apart to join said crest to the meeting point of the concave fold line at the base of said corrugation with those of the neighboring corrugations respectively, thereby making each one an angle of 15 with the corresponding base in each lateral face of said corrugation to terminate the latter at the zone of intersection, so that for a zero wave opening angle of said corrugations, said star points lie in the initial sheet surface of said plate element.

3. A plate element according to claim 1, wherein each pyramid has a substantially pointed vertex.

4. A plate element according to claim 1, wherein each pyramid is truncated to end with a substantially blunt vertex providing a small polygonal top face.

5. A flexible sheet-like plate element at least one portion of which is provided with n series of substantially parallel, spaced, identical, symmetrical, integral corrugations shaped as salient dihedrons of substantially uniform cross-section, projecting all entirely with their raised convex crest portions from a same side of said plate element without any projection of material from the opposite side thereof, the corrugations of each series intersecting those of the other series at common zones of intersection containing each one corrugation of each series and each substantially symmetrical about a central axis normal to the initial sheet surface, n being an integer greater than 1,

said corrugations forming a network consisting of adjacently juxtaposed convex polygonal meshes bounding therebetween smooth, uncorrugated, separate areas located in the initial sheet surface, each zone of intersection comprising a pyramid having its vertex on said central axis and protruding from the same side of said plate element as said corrugations, said pyramid having 2n triangular faces meeting along the edge lines of and forming regularly alternating, salient and re-entrant, successively adjacent dihedral angles defining corresponding ridges and troughs around the sloping sides of the pyramid and arranged by pairs in opposite relationship, said ridges lying in the bisecting planes, respectively, of the angles of intersection between successive corrugations whereas said troughs are located together with corresponding corrugation crests in the longitudinal planes of symmetry of the corrugations, respectively, the pyramid base being a 2npointed star-shaped, 4n-side, skew polygon, each re-entrant angle of which has its apex on the crest of a corresponding corrugation Whereas each star limb extends endwise between two successive converging corrugations with the corresponding star point lying at the meeting point of the two adjacent concave fold lines bounding the base of said two successive corrugations within the initial sheet surface whereby said star limbs are straddling said corrugations, and said plate element having a wholly geometrically developable surface throughout with merely folded features made in one piece with said plate element.

6. A plate element according to claim 5, wherein the corrugations of each series are equally spaced from each other and the corrugations of all series are uniformly distributed in angularly equidistant relationship about each zone of intersection to intersect at an angle of /n degrees with respect to one another, whereby said network is of regular pattern, consisting of regular polygonal meshes with regular pyramids at the intersections.

7. A plate element according to claim 5, comprising two series of perpendicularly intersecting corrugations, forming a network of checked pattern with square meshes, each zone of intersection being an octahedral pyramid with a four-pointed star-shaped base octagon.

8. A plate element according to claim 5, comprising three series of corrugations intersecting each other at equal angles of 60, thereby forming a network with equilateral triangular meshes, each zone of intersection being a dodecahedral pyramid with a six-pointed star-shaped base dodecagon.

9. A plate element according to claim 5, wherein each pyramid has a substantially pointed vertex.

10. A plate element according to claim 5, wherein each pyramid is truncated to end with a substantially blunt vertex providing a small polygonal top face.

References Cited UNITED STATES PATENTS 3,118,523 1/1964 Girot 52-573 3,321,881 5/ 1967 Alleaume 52-276 3,325,953 6/1967 Alleaume 52-276 3,299,598 1/1967 Alleaume 52-630 X 3,302,359 2/1967 Alleaume 52-630 X FOREIGN PATENTS 1,370,087 7/1964 France.

L. DEWAYNE RUTLEDGE, Primary Examiner J. E. LEGRU, Assistant Examiner US. Cl. X.R. 

